Others have already mentioned that any medical or surgical intervention could be termed interfering with nature.
Babies are an emotive subject, and instinct tells us that aiding survival in very premature babies is a good thing - but medical science is not infallible -all we are able to do is increase the odds that a very premature baby might survive. The hurdles to survival that a premature baby faces are immense - as just one example, they are born with immature lungs, which can lead to severe Respiratory Distress Syndrome, needing oxygen therapy, use of a respirator, continuous positive pressure within the airways, doses of surfactants. And even if they get past this, they run the constant risk of pneumonia.
And even if they do survive, the long term mortality and morbidity rates are significantly poorer than for full term infants, often suffering major medical complications as they develop through childhood.
These complications of survival, and the poor prognosis for those premature babies lucky enough to survive are incidentally the reason why medical evidence does not support the idea that the abortion limit should be reduced from 24 weeks to 20 weeks or less.
Whether we are actually interfering with the evolution of homo sapiens is an intriguing question, and one difficult to answer. Common sense might suggest that we are, but we have very little evidence to support that notion, and there is evidence to show that humanity is still evolving.